Automatic control for water-gas plants or the like



J. DANIELS 2252?;831

AUTOMATIC CONTROL FOR WATERGAS PLANTS OR THE LIKE *Y Aug. 19, 1941.

7 Sheets-Sheet l Filed April V2, 1938 #EIL . @6% MJ OQ 05 ab@ .Shuk

m82 QQ Jn vena/t' J. DANIELS Aug. 19, 1941.

AUTOMATIC CONTROL FOR WATER-GAS PLANTS OR THE LIKE Filed April 2, 1938 7 Sheets-Sheet 2 Jn Ven/of.'

DANIELS AUTOMATIC CONTROL FOR WATER-GAS PLANTS 0R THE LIKE Agg. 19, 1941.

Filed Apr-i1 2, 19:58l

J. DANlELs 2,252,801

GAS PLANTS 0R THE LIKE .Filed April 2, 1938 Agg. I9, 1941.

AUTOMATIC CONTROL FOR WATER- -7 Sheets-Shea?I 4 mum" Aug.. 19, 1941.

Filed April 2, 1958 J. DANIELS AUTOMATIC CONTROL FOR WATER-GAS PLANTS OR THE LIKE '7 Sheets-Sheet 5` 70 Y 775 u 94 48 lav 59 Wy m.-

.70 venfor:

Aug. 19, 1941. J. DANIELs A 2,252,801

AUTOMATIC CONTROL FOR WATER-GAS PLANTS 0R THE LIKE Filed April 2, 1938 7 Sheets-Sheet 6 Jn ven/or:

Aug. 19, 1941. J DANELS 2,252,801

AUTOMATIC CONTROL FOR WATER-:GAS PLANTS OR THE LIKE 1 Filed April 2. 1938 7 sheets-sheet 7 215 164 ,64 79 21 l l f lvl 4 2 767 165 v 7 6; v/

' 'l 1. f 1 Y' I y 764 r A n 765 79; 160 L- I l l leo 169 162 5 204 ).166 7g79 ,(790 790 'q [las /769 plants.

Patented Aug. 19, 194i AUTOMATIC CONTROL FOR WATER-GAS PLANTS OR THE LIKE Joseph Daniels, Essen, Germany, assignor, by i mesne assignments, to Koppers Company,

Pittsburgh, Pa.,

a corporation of Delaware Application April 2, 1938, Serial No. 199,6*88

In Germany April 2, 1937 14 Claims.

This invention relates to automatic controls for shut-off valves or other` closing means of water gas plants, blast-furnace hot Vblast'stoves or other purposes in which a series of means is to be moved, reciprocated for instance to open and closed positions in a determined sequence byl contrivances or devices which are operated by hydraulic pressure or compressed air.

The invention relates in particular to controls for the shut-off valves of intermittently Otherwise it may happen` that dangerous operating difficulties occur. If, for instance the air y lvalve is still somewhat opened so that air can operated' water gas plants and in the following description the present invention is described in more detail with special reference to this working field without, however, limiting the invention in all its aspects to use with water gas It is known to produce water gas in such a manner that a fuel, after being charged` into a suitable gas producer, is heated to a high tema perature by partial `combustion with air. whereenter the gas producer, while water gas is being generated in it by the introduction of steam, a

- certain quantity of air may enter the water gas so that highly explosive mixtures of air and gas might result. On the other hand, it is possible that some of the valuable water gas may escape through the chimney damper, if the same is not fully closed.

A great number of suggestions 'have already been made for the development of contrivances which make possible a fool-proof and proper reupon the air supply isstopped and steam is passed through the glowing fuel. The steam reacts with carbon at a high temperature with the formation of the so-calied water gas, a mixture consisting of hydrogen, carbon monoxide and carbon dioxide. .As soonV as the fuel is cooled down by the endothermic water sas reaction, the supply of steam is interrupted and air is introduced again through the fuel mass in order to heat it up again.

For the production of` water gas, it is often usual to employ a gas producer consisting essentially cfa shaft furnace, which is connected with the various pipe lines for the supply of air required for the' hot-blast, for the supply of steam, andfor the oiftake of water gas, and also connected with the chimney through which the combustion gases developed during the hot-blast period escape. Each of these pipe lines is controlled by a shut-off valve or another suitable closing means in such a. manner that the respective pipe lines are opened or closed at a given time. Often,` it is usual to make use' of hydraulic contrivances for the manipulation of the shut-oil. valves or the like, for example those operated by oil at high pressure. Manipulating devices operated by compressed air are also sometimes adopted for the valves.

As already mentioned, the shut-ofi valvesof a watergas plant have to be operated in a given sequence. It is therefore most important that each `individual valve finishes completely its movement, i. e. either the opening or closing movement before the following valve is actuated.

versal of the shut-olf means of water gas production plants. It has, however, been found that none of the known reversal or controlling apparatus answers fully the above requirements. i. e. to prevent' a movement of the shut-ofi valves in the event that one of them has not fulfilled its function at any time Without on the other hand causing other disadvantages with the use of these safety means.

The main object of the invention consists in the provision of a control for water gas plants or the like which is capable of fulfilling the following fundamental requirements:

(l) VThe control must be able to give a definite but variable sequence for the manipulation of the various shut-off valves.

(2) In case of diiculties, for example if any of the valves has not reached fully its end position, the further reversal of the valves must be r interrupted automatically at once. A,

(3)` The time between the actuation of the individual shut-oli valves must be highly variable and on the other hand accurately adjusted.

l(4) No alteration in the sequence or in the operating periods must reduce the safety of the plant against faulty operation, or in other words. no alteration must stop the shut-off means from acting to prevent the further movement of the controlling apparatus in caseof mistakes.

(5) Finally, it mu'st be possible to make alterations to the position of the individual shut-off means by hand at any time, without changing the control in its entirety.

The formervautomatic controlling apparatus for water gas plants generally consisted `of a control similar to a reversing clock which` at a given time and in a given sequence manipulated the valves, through( which the pressure medium passed to the various valve operating cylinders to be operated. With the known controlling apparatus, difculties arose `by reasonnoflthe sticking Aor incomplete closing Aof vvalves r or .the .like without stopping the controlling` apparatus. lThe operator supervising :the .apparatus was. relied upon: to'. stop thef'controlfhe ybeing able .in such 'cases to ,press` push buttonszonthelike by; means of which the-.clock wouldbef-putout'of; operation `andthemovement of theother shut-o'i valves stopped.

`With the vcomparatively quickly :succeeding- `re versals `required .ofgthe numerous cut-oir l.valves of a water gasfplant,-a. control: machinist canino longer be. expected to* give the uninterrupted. :at-

tention whichl is. necessaryin Aorderftov watch `over large plants.

.I- have 4already describe'd..inr ;my 1U. '8.1 patent application 'Serial lNo. 189,241,11ed 'February 1"?, 1938, a new improved control or .switchzmech- VVanisrn'rfor several .cut-oivalves,` preferably "those of blast --furnace hot-blast'st-oves i ofgthe lCowper System ortheflike. y l V v The control formerly `.describedworks `fully y waterfigasprocessthemethod-ofsprocedure may bethat'seenlfrom thediagram; illustratedin Fig- `urellaoifthedrawings.

i iThe" diagram: is .intendedrito illustrate-.a Ycycle fof .aMateregas plant -fwhich hasa vvchimney :valve controlling" the connection of fthe' gas: .producer `to .therchimnema primary:valve for .thetprimary air which iszblown .under'fthex grate,...a secondary air valve f ori-secondary ;air' which. isl .blown `.into-the 'upper1 part of. the gas' producerin Vorder to .burn

the combustible constituents of the so-called hotblast .or blow gasespa purging-steam.valveffor a -1 purge .steam pipe 'through iwhich steam Alis supplied .for purging the smoke -or hot-l-.blastffgases .from :the gasrproducer, 'a Awater=gas` `valve-:for .the".up- `run .Water .gas olltake pipe v`foraoiitalre of .iwater l gaswhich 4'comes .from..the spaceabovejthe fuel automatically. Therein I usestop ori'b-locking valvesfwhichare operatedby the shut-o'fjvalves afterfreachinga given end position. If .onecof tliesegshut-.of valves does `not come :into .its proper end i position, Ythe .movement of L. the Afre `mainingvalves Vis prevented at once. `The automatic control .as f described in .m3/ prior j. patent application is vespecially :suitable :for "Cowper `stoves.onsimilarplants 'in which the valves `need not bexreversed. so oftenand inwhich, except for onevalve forA example-servingto govern-.the v delivery of` Washing steam,.all other Avalves are g opened or. closed only once duringone run.

In water gas .plants it is,. howeverjnecessary to open and close lmore than once within a single operating period or cycle certain'valves yand it is necessary toproviderfor an adjustablepause between the opening andclosingas required by the waterigas production process.

In order both to meet` this requirementand to Y Iull all theother conditions already pointed out above asbein'g'necessaryfor a proper sequence control apparatus for water gas plants or the like, and at the `same time make use of the simplest V possible lreversal 'processes and means, .I have now developedanew and improved .sequen-' tial control'apparatus.

'Moreoven "my invention `alsoextends `to the means'for the operation of.` thefuel supply'members which. are `provided on the gas-.producer .for introducing :the ffuel. l

Theiinvention extends .in particular :to .appayratus Sforxthe production of 'waterfgasaccording 5f to thesocalled intermittent process. .In this type of water-gas production, fuel introduced into theagasproducerfisrst of fall heated to 1a'. high temperature .by blowing .air1through ..the1fue1. Steam is Ythenintro'duced into vthe .heatedffuel yand combines `with the carbon `forming the :socalledwater-gas `a mixture of` hydrogen. carbon `monoxide .and carbondioxide. As` soon as the Infthe practical operation ofthe discontinuous 5 :part-fof the gasxproducer.

1bedofihe'generatonasteamingvalvev for .up-run steam which is .blownaun'denthegrateSforlhc productionv .'of;water-gas-.a .water-.gas .Valve'to lwithdraw .down-runv -iwatergas from "below the base.l of the `generator withV socalled i-.gasifying ywith..downgrun steam," from above.gandinallyv a Avalve steaming f to introduce l'down-rmi. .steam,

during the gasification from .aboveintotheuppcr These eight valves or slidesyofthefwateregas ipjlant eare tollbe operated in a :certain =way2which .can loev seen f rom the 4diagram` .of` 'Figure l. 1. The

`arrow, indicated byv ar iii/Figure .1 giveslthe'direotion in 'whichf thejfsymbols 1. forv the processes .are to 'be" 'read on the iigure toain'dicate when. .they

`follow each other. Theirelativeqpositionfof the ringthej period during whichtthe separate valves lare closed indicated, by shadedsareas. in the .'diagram .and by; having-y the periodA during :whichfthe valves .are .open'indicated .by non-.shaded areas.

.Assuming that thegenerator is at astage. when it has been cooled down' frornav precedingdown run water-.gas operating.: period :and '.that -ithe chamber under. the.` grate, .which was filledk with Water-gas, .has been .washed iout-.by introducing "purge steamffor a shortzwhile. Duringithe short washing or 1 purging,vv the Vchimney damper has alreadybeen opened. .Assoonas the introduction Y 'of thefpurging steam: has Aiinishedthe mainror 'primary air valve is thenopenedso'thathot-blast air can ow` under .the grate. Shortly after. the 1 opening of the primary air valve, .the secondary air -valve is v.then ralso ropenedgso 1 that the hot.

r blast gasesaccurnulating in the upperpart'of `the vgenerator-can be `burntlgThls isfoilparticular. ad-

vantage ifa* regeneratoraserving .to Aprei-'heat-the I :gaseous Water-gasxmalring Vsteanijis fconnected" "with theegas producerjand is 'heated' up duringthe hoteb'la'st .periodby-fthe hotlblowigases. .As

' A `soon-asthe charge of f, thegasfproducer'zis Hsuiiimary :air valve are fagain e `closed ..and'i'then ithe Apurging steam Valve'is openediforarperiodisui cient;` to extract the hotblast gases `from the 1 gas produceraridthe adjoiningiregenerator.

The-'purging steam .valve v is "then .closed and y shortly .after-.wards the. chimney fwdamper valvefis valso closed. The upperluperunwater-gas'.oitake valveis Athen .opened-.and shortly 'afterwards the up-:run steam valve .through'which -gasifying steamis blown .under the *grate is opened. "This 1 operating; period is .indicated in the '.diagram.v by l.terms f-upfrun,fWater gas'valveabove, .and ysteaming b`e10w;gra-te. .Aftera certain timethe v .direction of :make .isaltered. 'For this V:purpose the `upper water -gasvalvexand'.the lower.' uprun steam Vvalve are .closed andy the lower `h.downerun ated by thehandi leveri- 3l.

"cumferentialfcamz ,tof `thefangle leven-Bulls fixdfi'rr position. .The .end of. .theangle-.lever 130;. under.` vthe action of y springsr `32 1 and a connecting frodi 33, actsi oni V4the valve control?. lever .34;nwhi'chrpivots" about the g -pointzl ,short'time :the purge steam" vvalve is opened `in *order to drive out thel Iresidual watengas .from

fthe spaceibelowthegasl producer grate andin the 1 gas:l producer andl regenera-tor.` J-As lsoon as .the

shortpurging` has finished .the'cy'cle starts anew with theopening: of.primary!` air. valve. --In this way the operation is continually repeated.`

f The devices which: make possible the. movement` i' of 'the' valves according tothe diagramV off Figure v l areillustrated by way-of example in Figures 2;-7' of the drawings.

":The drawings show the two air valves which are l. operated4 during the blastzperiod and 'the valves which are operated for iiow of `steam downwardly from above'.duringdown'frunsteaming together with the corresponding coiitroldevice therefor. The control" device foi` .the other reversing: means for the other devices are similarly constructed so that a further description of. thc-same is unnecessary. Y j

i The actual Aconi-mii plant. is arranged inf` a'` clos- .ableucabinet-likehousing rIf.A On the .front side 'th'elh'ousingv hasacl'osabledo'or; 2 which in the closed? position is held byl means of. boltv 4J oper- Inlthe control' or switch cabinet. therefis intro- ?duced' a. pressure mediumlthrough the main pressurewrnedium pipe'5,` w'lriclrleads from a compressing dcviceiwliichvfor th'esake'of simplicity is L not` illustrated on :the drawings;

*"Preferabl'y, the.` device:v f asV .illustrated on. `the drawing.` is supplied` Witlpoil 'athi'gh pressure for the operation of 'the cut-oliI valves. and. controlV devices.. However,. instead off pressure foil', pressure water. or: com-pressed" air canzal'sobejused.

F 'From "the switch:r :cabinet` awpipe` 6 -leadsv oil which: has lost its pressure" back to; a connecting v d'evi'ce'iorv example; tol a l pressure oil. pump.

".Inffthe drawing.. Fig. I 5; the `main airv valve Vis .indicated at `|,;=thesecondaryfalr valveiat': 8, the lower down-ruxnwater gas` oil take valve. ati 9"t and: `f .ithex:.` upper 1 ilown-run.` 'steam' valve: 1 at U10'. ."I'he 1. are.. seated mathe,I usual. housings.' asf-.illus- :.itratedrs'chem'atically.ninth drawings.

.120; zum

'Inside'ther 'switchf cabinetfthere is provided on In the range i-ofimoveme'nt of theA circumferen- .tiall cam 2.1V there is'provid'cdy anwangle lever 30. If the camf disci rot'ateswinf aclockwise .direcltion the` angle lever 3 f-isl movedl on .its pivot `in the direction; of thefarrow' by means ofthe cir- "LThe'point of rotation` 3| 1 From the valve lever 34. Thev rods 36,Y 31 each act on a whichI are 'preferably `arranged `in a common housing 42. "'Thechambers' onr lone side of the valves 4| and v39 are connected with each other 'through the passage 43 and the chambers on one side of valves4 38 and 40 through the passage 44.

"The chambers lying on the other side of the valves`39and' 40 are connected with each other vthrough the pipe 45 and similarly as to the valves 38 and 4| through the1pipe46.

As can kbe seen. from the drawings the pres- `sure'oil pipe 5 is connected with the upper chamber of the valvel4| by means ofpipe 5a and a reversing cock 4`| (Fig. 2), the function 'of Whichwillbe explained hereafter, the pressure oilpipe 5a lying on the inside of the switch cabinet;` QL

' From theposition of the valves in the housing `4i it canrbe' seen that the pressure oil can flow through the open valve 4| upto the front of the closed valve 38, and in addition from the chamber of the valve 4| through the pipe 43 up to the closed` valve 39. From the pressure oil 'piper 5a there extends a branch pipe 5b the function'y of which will be explained hereafter.

Assuming that the circumferential cam 21 of the cam disc 26 of the control shaft 23 has moved the angle lever 30 whereby the position of the valve control lever 34 has been soy altered .that the valve rod 3l goes downwards and the valve rod 3|i-is raised. In this waythe valves 4| and 40 are closed and the valves' 38 and 39 are opened.

Accordingly the pressure medium current is free` tolflow` through the valve .39 and on the yother'ha'nd as the valve 4| is closed the current of pressure medium to the valve 38 is interrupted. The pressure medium can now flow through the connecting pipe 45 into the upper chamber of the'now closed valve 40. From there fthe. pressure medium flows through the pipel 48 into the lower chamber 49 of the hydraulic device lI9 (Fig. 5) through which the main air valve is operated. The pressure medium raises the piston l5 upwards and thereby opens the I main airk valve v|. During `the upward movement ,ot'the piston rod a'cock 5| is reversed by means of an adjustabledetent 5D provided on Athe piston rod the plug of said cock being provided with. a correspondingly shaped forked .lleverw5`2,iin which the .detent 50 engages. The

cock 5| controls thepipe 53 which is in connection with the pressure `medium pipe-48. A'fter openingthe` cock 5|` the pressure mediumcan vair valve 8. `through the pipe 54 raises the piston I6 whereby thus flow from the pipe"V 4B through the pipe 53 and the cock 5|v into thepipe 54. The pipe 54 leads to the lower cylinder chamber of the hydraulic device 20 which operates the `secondary The pressure'medium ilowing in the secondary air valve is opened.v

O n. the piston rod |2 of the secondary `air .valve there is likewise disposed an adjustable vdetenti55 in the range of which the fork-shaped adjusting lever 5B of a three-way cock 51 isdis- :posed On thelupward movement of the piston rod this three-way cock is reversed in such a way'Y that the pipe .58 which leads from the pressure medium pipe 54 is connected with the pipe 59.

Atthis period the two air valves are thus opened sov that the blast period of the water-gas' process can be carried out.

VAssoon as the cam` 21 of the control disc 26 has come within reach of the lower end of the angle lever 30 and the lever has moved the stem 36 up and stem 31 down in the housing 42 with the reversal of the valves, the check cam 28 on the side of the disc 26 abuts against a bolt 616 which is movable longitudinally in the switch cabinet. The bearings for the bolt 60 are for the sake of simplicity not indicated.

The bolt 68 is connected through the rod 6| nected by means of the pawl 83 and ratchet wheel 84 with a worm wheel 85a, in which the worm 85 engages. The worm 85 rests on a shaft 86 which is disposed in the switch cabinet.' The shaft 86 is constantly rotated by means of a reduction gear 81 (Fig. 2) and an alternating curwith a piston 62 which is arranged in a hydraulic cylinder 63. As the check cam 28 rests against the bolt 60 the cam disc 26 is maintained in arrested position and therefore the rotation of the control shaft is interrupted. It is obvious, however, that the drive of the control shaft is not thereby interrupted so that the control shaft 2.3 can immediately rotate after the check bolt 6l!) is brought out of range of the check cam 28. The check bolt 60 is Withdrawn in the device illustrated immediately after certain further stages in the movement of the valves or of the entire control device have been satisfactorily terminated. I

VThepressure medium iiowing to the hydraulic device of the secondary air valve passes-as already mentioned-after reversal of the threeway cock 51 into the pipe 59 which leads back into the switch cabinet. The pipe 59 is connected to one chamber of a valve 64 which is provided in-a housing 65 in the switch cabinet. In addition the pipe 59 is connected With the larger cylinder chamber 66 with a piston 10 of a differential piston device 61 which is disposed in the switch cabinet, by means o f a short branch` pipe 59a. The device 6 1 has in addition a smaller cylinder chamber'68 with a piston 1|. The pistons of the device 61 are fixedly disposed as indicated at 69. `The cylinder-like housing of the device 61 is movable between the pistons.` The larger piston 18 and the smaller piston 1| have a longitudinal bore through which the pressure.

medium can flow into the cylinder chambers. The longitudinal bore of the piston 1| isconnected with the pressure medium pipe 5b which is permanently charged with pressure medium, so that the smaller cylinder chamber 68 of the device 61 remains permanently under the pressure of the pressure medium. As soon as the pressure medium acts through the branch pipe 59a on the larger cylinder chamberl 66 of the device 61 the cylinder housing 61 is moved in the direction of the arrow 12 whereby Athe resistance in the smaller cylinder chamber 68 is overcome by the larger force in the cylinder chamber 66; t On the cylinder 61 there is provided an adjustable detent 13, which on movement of the cylinder housing 61 comes'within the range of an angle lever 14 which pivots about the point 15. The angle lever` 14 acts through the valve rod 16 on the valve 64. On the axle 15 therev is also provided a lever 11 which is coupled for movement with the lever 14. The lever 11 acts through the valve rod 18 on a valve 19 which is provided in the housing 65. v

The cylinder housing 61 cannot move at any random speed in the'direction of the arrow 12 but vthc time which the cylinder 61 needs in order to come into the other end position is accurately rent motor 88. The driving device for the shaft 86 is preferably arranged outside the switch cabinet. 'I'he connection between the gear wheel 8| and the worm 85, as through the pawl 83 and the ratchet wheel 84, (shown as drawn to a larger scale in Fig. 8) is lconstructed in such a way. that the gear wheel 8| can rotate quicker in a clock- Wise direction than the worm wheel 85a whose movementy is determined by the rotation of the worm 85. In the opposite direction the gear wheel 8| rotates as fast as desired and independently of the movement of the worm wheel 85a and the worm 85 pawl 83 idling over ratchet 84.

`As soon as the detent 13 abuts against the angle lever 14 the operations of the control device which are necessary to close the air valves 1, 8 are instituted. On account of this it is possible by suitable'adjustment of the detent 13 accurately to adjust the time during which the air valves 1 and 8 are opened. Obviously, in the arrangement illustrated the detent 13 is always moved at constant speed in the direction towards the angle lever. The speed is kept constant by the device 88, as described. If an alternating current motor is used the speed of rotation of the device 88 adapts itself according to the periodicity of the alternating current used. It isfobviously also possible to use instead of an alternating current motor any other driving device `which operates with a constant speed of rotation.

Ifthe detent 13 moves the lever 14, the valve 64 is opened and the pressure medium can now l brought out of range of the check r'cam 280i thev cam disc 26. On this account the carri disc 26 and the shaft 23 can vrotate again. In this way the circumferential cam 21 cornes out of range of the angle lever 30. vThe angle lever 30. is now moved back into its original position which corresponds tothe position shown on the'drawings through the force of the spring 9|.

As soon as the circumferential cam 21 has come outv of range of the anglele'ver 30 the check'cam 29 on the side of thecam disc 26 abutsI against an extension 92 of the check bolt which has come within range of the check cam 29 through movement of the check bolt 60 in thedirection of the arrow 93. In this way the movement of the cam disc 29 is againstom'ied.l

Through the reversal of the angle lever 30 in'to the position shown in the drawings the valves v38, 39, 40, 4| likewise assume the position shown on the drawings.l On this account the current o f the pressure medium from the pipe 5b through the previously opened valve 39v the fixed axle 82. The gear wheel 8| is con- 75 4| and which leads to the upper cylinder chamber of the hydraulic device 20 of the secondary air valve. The secondary air valve is on this account moved downwards and the three-way cock 51 is thereby reversed, that is, brought into the position shown on the drawings. In this way the pipe 59 is brought into connection with the pipe 95 which leads through the valve housing 96 winto the pipe 91 for thepressure medium released from pressure and is connected with the main pipe 8 for pressure medium released from pressure. On this account the pressure oil in the larger cylinder chamber 99 of the differential piston device 91 can release its pressure and the cylinder 81 is now moved in the opposite direction to the arrow 13 by the pressure medium into the smaller cylinder 99, which is permanently in connection with the pressure medium pipe 5. In this way the pawl 80 slides idly over the teeth of the pawl ratchet wheel 84. The device 81 is thus likewise brought back into its initial position.

If the secondary air valve 8 has come into its lower end position in which the air pipe is satisfactorily closed, a detent 98 provided on the piston rod` |2 abuts against an angle lever 99 which acts by means of a rod |00 on a valve |0| which is arranged in the housing 96. 'I'he actuating lever 99 which can pivot about the fixed axle |02 is under the action of a spring |03 so that when the detent 99 moves upwards valve |0| is automatically drawn into the lower closed position.'

'Ihe valve 0| is opened by the movement of the adjusting lever 99 effected by the detent 98. The upper chamber ol' this valve is connected by means of the pipe |04 with the pressure medium pipe 94, that leads to the upper cylinder chamber of the device 20, and through which pressure medium ows at this period. The pressure medium now flows through the opened valve |0| into a connecting pipe |05 which is provided in the housing 96 and p'sses from there into Aa pipe |09 which leads to the upper cylinder chamber of the hydraulic device |9 appertaining to the main air valve The pressure medium entering in the upper cylinder chamber of the device |9 moves the working piston |5 of the valve 1 downwards, whereby the main air valve is closed. If the valve 1 finally reaches the end` closing position an adjustable .detent |01 provided on the piston rod acts on a valve lever |09 which is constructed similarly to the valve lever 99. The valve lever |08 opens a valve |09, disposed in the housing ||0, when it is moved upwards in the direction of the arrow. A spring |||a is provided and draws the valve lever |08 downwards as soon as the detent |01 comes out of range of the valvelever |08. The spring |||a thus servesrto close the valve |09 automatically.

If the valve |09 is opened, pressure medium can flow from the pipe which is connected with the/ pipe |09, through the chamber of the valve |99 and a pipe 2 provided in the valve housing, into the pipe |3. This pipe 3 leads to the right cylinder chamber of the hydraulic device 93 in which is disposed the operating piston 92 for the check bolt 90. 'Through lthe pressure medium the piston 92 is moved back towards the left into the position shown in the drawings. The check bolt 90 is moved correspond ngly and in this lway the extension 92 of the ch k bolt 60 is moved out of,the range of the check lcam 29 of the cam disc 29. The cam' disc 28 is now freed so that the control shaft ,23 can again rotate further.`

The control shaft 23 continues to rotateuntil the circumferential cam ||4 of another cam disc ||5, which is disposed on the shaft 23, moves within range of its valve operating lever ||6 which is constructed similarly to the valve operating lever 30 for the cam disc 26.

The control shaft 23 thus also carries other different cam discs, viz., a cam disc for the chimney damper, and further cam discs for steam valves, water-gas oi'ftake valves, and the like, according to the construction of the water-gas plant. The cam discs are all similarly constructedso that the control shaft is always held stationarily in position during the movement of a valve or a valve group'fand is only freed again after the movement ofthecorresponding valve or valve group is satisfactorily terminated. It is immaterial how many cam discs are in this way arranged on the control shaft 23. However, the arrangement of the cam discs and their diameters must be such that the cams of the different discs do not actuate their corresponding bell crank levers (e. g. 30) at the same time.

The valve housing ||1 co-operating with the rcani disc ||5 is connected through the pipe-line in a similar way to the device 91 and is connected with the shaft 99 which is kept rotating at constant speed. As soon as the time measuring device |20 has completed its stroke and the valve lever |22 has been actuated by the adjustable detent |2| theltwo valves 9 and |0 are again closed with the corresponding operation of the check bolt |23 which co-operates with the check camsr |24 of the disc 5. After termination of the movements of the valves 9 and I0, the cam disc ||5, and with it the shaft 23, can rotate again either to bring a further disc disposed on the shaft 23, into action or to set in operation the first of the cam discs so that the cycle then may commence again from ythe beginning.

For the valve |0I, |09, etc., actuated by the slides 1, 8, 9, I0 in their lower end positions, special devices are also provided in order to stop a further iiow of the pressure medium, if for any reason any one of the pressure medium valves, controlled by the slide valves T, 8, 9 and l0, fails to operate. This safety device which is present with all the slide valves y'|, 9, 9, |0 is described with reference to the arrangement of the slide valve 1.

.With the valve lever |08 which can rotate about the xed axle 230 there is coupled a second If the valve |09 is opened .the

The pressure medium flowing into the valve housing I through the pipe I I can then only act on any other device if the valve is closed, that is, if `the valve levers |08 and |24 are brought into a position corresponding to the true end position of the valve 1. If the valve |25 is not completely closed the pressure oil flowing into the housing I|0 from 4the pipe-line would escape through the open valve |25 into the pipe |26 for pressure oil released from pressure and no pressure oil would flow into the pipe |I3 which leads` to the operating device of the check bolt 60.y In this way a simplev but eirective safety means for guardingagainst faults in the operation of the valves |09 and |25 is obtained. A device is also provided in order to put the time measuring devices '61 and |20 out of operation by hand. For example, in water-gas operation it may under some circumstances be desirable to shorten the hot-blast period for an exceptional reason.

In order to put the time measuring device 61 out of operation for such contingencies there is provided the three-way cock ||9, and in order to putthe time measuring device |20 out oi' operation there is provided the three-way cock |21. The two three-Way cocks IIS, |21 are each disposed in a pipe line through which pressure medium flows .to the control valves for the next cam disc.

Moreover, the three-way cock |I9 is connected through the pipe |28 with the pipe |28 which is connected to the pipe 6 for pressure medium released from pressure, which lies in the switch cabinet. In a similar way, the three-way cock |21 is connected through the pipe |30 with the pipe |3| which is likewise connected to the pipe 6 for pressure medium released from pressure, lying in the switch cabinet. `The reversing cocks ||9 and |21 are actuated by means of hand levers |32, |33 which project outside of the switch cabinet and can be reversed by hand byl the operator of the plant. On the hand levers |32 and |33 there are provided projections |34, which lie in the range oi.' the valve lever 11 and the corresponding valve lever |36, which cooperates with the cam disc 26 and ||5. If the hand lever |32 is moved in the direction of the arrow so that it is rotated 90 with respect to the position shown on the drawing, the threeway cock II9 connects the pipe-line ||8 with the pipe |28 for pressure medium released from pressure and the connection between the pipe ||6 and the pressure medium pipe 5b is broken. Simultaneously, the valve 19 in the housing 65 is closed and simultaneously the valve -64 l the valve lever 14. .The position ot the valves then corresponds to that which they assume if the detent'13 of the time measuring device 65 had operated the valve levers 14, 11. 'I'he pressure medium thus flows through the housing 65 and now acts on the operating piston 62 of the check bolt 60. On this account the check cam 28 of the cam disc 26 is free and the cam disc 26 can rotate further by a certain amount so that thecircumferential cam 21 moves out o1' range of the lever 30. This has the result that the lever 30 is withdrawn under the action of the spring 9| and the valves in the housing 42 are reversed so that the closing movement of the valves 1 and 8 begins. At the same time the hand lever |32 must then be swung back into the position indicated on the drawings whereby the pressure medium pipe 5b is, again connected is opened by with the pressure pipe I|8 leadingltothef two valves and the `latter valves are set in operation. If the hand'lever |32 is not moved back into the position shown on the drawings thecontrol shaft'j 23 rotates further until the outer lateral Vcheck cam of 4a cam disk, for example,4 the. check cam |24 of the cam disk IIS, rests :against `the corresponding check bolt (|23 for the disc IIS). Then the valves in the housing ||1 are` also operated through the circumferential cam oi the disc ||5 (as described for thevhousing 42).

However, no movement of the corresponding cut-` oif valve is possible since the supply of pressure` medium through the cock IIS isinterrupted. As soon as the cock IIS has again returned to the position shown on the drawings, pressure medium ilowsto the housing ||1 and from there to the cut-off valves 9, |0which are then opened.

In the same way the time'measuring device |20 can befput out of operation by means of the hand lever "|33,

I The hand levers |32, |33 are thus used if the I time interval during which one oi'- the valves or groups of valve is usually opened, is to be shortened. If this time is to bel extended the eccentric levers |31 and |38 which are provided on the valve levers 14 and 22, respectively, are moved in suchv a way as to move the engaging rollers shown for the detents out of thepath of the detents 13, |2| so that the ends of the levers 14, |22 are outsidethe range of actuation by the detents 13, |2| of the time measuring devices. The time measuring device can then be moved completely into the other end position without the detents 13, |2| acting on the valve levers. This means that the valves 1- and 8 or 9 and I0 can remain open-as long as desired until the eccentric levers |31 or |38 are again moved'into'the position shown on the drawings.

In Figure 7 of ,the drawings there is shown t schematically` the operating mechanism for the device for supplying the gas producer with fuel. On the cover |40 of the gas producer, there is provided an opening, closable by means of a conical b'ody.|4|, which leads to a charging hopper |42. 'I'he closing bodsr |4| is carried on an operating rod which passes through the cover .of the hopper housing |42 and is connected with the piston |44 of a double acting hydraulic c ylin- The hopper housing |42'` is fed with theffuell from a pipe |46 which is controlled by a valve |41a. To the pipe |46 there isconnected the lower end of a supply bunker |41.k The-connec tion between the fuel bunker |41 and the pipe I |46 is controlled through are connected through the piston rod I 40 with the piston 50 of a hydraulic device |5I. Thedevice serves to open or close the ilap's |48 as required.

For the operation of the closure valve |41a there isv provided the hydraulic device |52, whose piston |53 is connected through the piston rod |54 with a rack |55 which engages the gear wheel |56. The gear' wheel shaft |51 carries at the other end the gear wheel |58 which engages a rack |58 connected with the cut-off valve |41a.

For the operation of the supplying device there is provided a series of cocks |60, |6I, |62, |63 which can be operated by means of the hand levers |64 and are disposed in the neighbourhood of the4 supply device so as to be easily accessible by the operator of the plant. The cocks |60, |6I,

closure naps I 48 which in the meantime.

the cockshcan only vbe moved in the direction from leftt'o right on the drawings. If, for example, the cock |60 is rotated insuch4k a way 'that the handle |64 assumes a position vertically to the position shown on the drawings then a recess |69 of the disc |65 comes within the range of rotation of the disc |66 which has a recess |10 and a recess |1|. i The `recess |10 allows rotation of the disc |65. When the recess |69 lies opposite the disc |66, the disc |66 can be rotated by 90. With this, however, the disc |66 engages in a recess |12 of the disc |61'. The disc |61 canthus only be rotated if `the disc |66 has the position shown on the drawings. Finally, the disc |66 can only be rotated if the recess |13 of the disc |61 is turned towards the disc |68.

The charging of the gas lproducer is best effected during the so-called gasication from above, that is, during down-runs. During the gasification from above steam is introduced from above through thegas producer charge so that thel space above the gasifyingcharge and below the gas producer cover |40 is lied with steam at low pressure. The time measuring device '|20 relating to .the cam disc i i5 may determine the duration of the so-calledgasication from above. As

soon as the gasification from above hasbegun the the operating device |45. On this account thc piston |44 of the operating device |45 is moved downwards and the closure body I4| is lowered in the gas producer so that the hopper housing |42 is in connection with the gasifying shaft. The

fuel inthe hopper |46, |41 cannet fail over into the gasifying shaft during this time. As soon as the hopper |42 is discharged the lever |64 of the cock |6| is again brought into the position shown on the drawings. Through the cock |6| thepipe |66 previously lled With pressure medium and ,the member co-operating therewith is connected pressure medium entering into the upper cylinder pressure medium `remains in the 4pipe |14 (Fig. 4),

which leads to the housing |15 in which lie the valves |16, |11 which are moved by movement towards the right of the time measuringdevice'glZU, Thehousing |15 has a pipe |19, coming from'the chamber |18 of the valve |16, to which is connected `a pipe |80, .which leads through a. threef way cock |8| (Fig. 7) the function of whichwill .be explainedhereafter, to the reversing cock |60. The pipe |90 is thus lled by pressure medium when the time measuring device |20 starts to move. ,i l On the other hand the chamber of the valve |11 of the housing |15 is in` connectionwith the pipe |82 which corresponds to the `pipe 90 in the de- `vice Withthe cam `disc 26. The pipe |82, however, does not lead directly to thehydraulic device |83 for the check bolt |23 but leads first of all to the reversing cock |60. From the reversing cock |60 the pipe |84` then leads to the actuating device |83 for the check bolt |23. In the position of the cock |60'shown on the drawings the pressure mediumcan thus ow from the housing |15="a`fter` operationof the lever |22 by the time measuring vdevice |20 into the pipe |82 and` from there into' the pipe|84 so that after the running4 down ofthe time measuringvdevice the 'check bolt |23`is operated in the described manner. Howevenas soonlas'thefcock |60'has been moved by means of the handle |64 in order to operate the fuel supply device the connection between the pipe `|82andthe pipe |84 is interrupted. Thus', no pressure medium can fiow to l the operating device sa of the check bolt |23 until the fuel supply device of the `gas producer is restored again` in the position'in which |4| isin closed position, independent of whether the time measuring device `|20 has or has not run down Through movement of the cock |60 the pressure` medium pipe |80 is conlnected through the pipe |85 with the cocks |6|, |62, |63 which at this moment. however, are still closed. Then by operating the` hand lever |64 the cock 6| is rotated by 90. V pipe |85` is brought into connection with the pipe |86 so that the pressure medium can 110W through avalve housing |81 into the pipe |96 and from there into the upper cylinder chamber of 75'- In this way the' l actuating piston |44 is moved upwards by the chambe, against the pressure medium in the lower cylinder, chamber. If the upper cylinder chamber of the device |45 is now connected with Ithe pipe for pressure medium released from.

pressure, by means of the pipe |88 and the valve housing |86, the cock |6| and the line |89, the

pressure medium flowing from the pipe |00 and the filling hopper |42 of the gas producer is the position shown on the drawings, so that the thereby closed.

The cock |60 can now again be moved into pressure medium can flow after the running down of the time measuring device |20, through the pipe |82 `into Ithe pipe |84 to the operating devicel |83 of'the check bolt |23. By operation of the check bolt |23 the movement of the control member proceeds.

The fuel hopper |42 of the gas producer is now to be recharged with fuel. Should this take place during the running down of the time measuring` device |20 the cock |60 remains in open position so long as the pressure medium pipe is to remain in connection with the pipe |85. The cock |62 is moved so that the pipe |85 is connected with the pipe |93 which leads through4 a valve housing |94 to the pipe |95, which leads to the lower cylinder chamber of the operating device |52. The valve |96 disposedin the housing |94 has in the meantime been opened through an adjustable detent |91 on the operating rod |98 of the piston |44. For this vpurpose there is provided an operating about the-fixed pin 200. The valve |96 is thus opened in the closed position of the closure body |4l. If the closure body |4| moves downwards the valve |96 is automatically closed by the spring 20|.

The hydraulic de vice |52 is likewise constructed as a differential piston. The upper cylinder chamber of the device |52 is connected through the pipe '202 with the pipe 9| and is thus permanently charged with pressure medium.

The pressure medium flowing through the pipe into the lower cylinderl chamber after reversal of Vthe cock |62 moves the piston |53 upwards since the pressure surface on the upper side of the piston I.|53 is smaller than that on the'underside. By raising the piston |53 the rack |65 is alsoraised and therefore .the shaft lever |99 which rotates |51 is rotatedin aclockwise direction. On rotating the shaft |51 thegear wheel |50 moves the rack 559 in the direction of the arrow 203,

whereby the closure valve/ |41a is withdrawn from the fuel supply pipe |46.

The cock |63-is now rotated by means of its hand lever |64 so that the pipe |85 filled with .pressure medium is connected with the pipe 2041. The pipe 204 leads to a valve housing 205 in which a valve 206 is disposed and on the other hand the valve housing 205 is connected with the pipe 201 leading to the lower cylinder chamvber of the operating device which serves to operate the closure iiaps |48 of the fuel bunker.

The rack |59 of the closure valve |41a has a detent 208 in the range of which lies a lever 20S which is .connected with a cam shaft 2|0 which on the one hand acts on the valve 2|| in the valve housing |81 and on the other hand on the valve 206 in the valve housing 205. Through the action ofthe spring 2|2 the cam shaft 2|0 is held in such a Way that normally the valve 2| is the charging pipe |46 is closed.

If the closure valve |41aI is withdrawn as described above, which is only possible by means of the position of the recess |1l on the cock disc |66,'if the closure body |4| is closed, the detent`208 moves the camshaft 2|0 in such a way that the valve 2|| is closed and therefore the valve 206 is opened.

Through the opening of the valve 206 the path from the pipe 204 into the pipe 201 is freed to pass the pressure medium so that the closure flaps 48 of the fuel bunker are opened. Fuel can thus only be allowed to iiow into the hopper |42 from the bunker |41 if the closure valve |41a and the bunker flaps 48 are opened. v

As soon as the hopper |42 is recharged th fuel aps |48 can be closed. This is effected by moving the cock |63 into the position shown on the drawings. In this way the pipe 204 is connected with the pipe |80 so that the pressure meber of the operating chamber |5| which is like- 4:als

wise constructed as a diierential piston is connected'through the pipe 2|3 with the pipe |9| permanently filled with pressure medium. On this account the piston is now moved downwards and the aps |48 are closed.

After moving the cock |63 the cockl |62 can again be brought intov the position shown on the drawings. In this way the pipe |93 is connected with the pipe |69 for pressure medium released from pressure, so 'that the piston |53 is moved downwards into the position shown on the drawings under the actionof the pressure medium flowing in through the pipe 202.

All valves and flaps of the supply device are now closed and are brought into the position shown on the drawings.

The cock can now be moved again into the position shown on the drawing`s\so that the pressure medium can effect the further movements ofthe control members.

In order to operate the supply device of the 'gas producer at any desired time thereis provided the cock |8I. The cock |8| is a three-way cock and can be actuated by means of the han-I dle 2|4. By movingr the cock |8| the pressure medium pipe 2|5, which Ais permanently connected with the pressure medium pipe |92, can be connected with the pressure medium pipe leading,7

to the cock |60 whilst at the same time the pipe ing to the cock |8|7, the pressure medium can flow into the operating cylinder of the fuel supply device.

As has already been described above the pressure medium for thc actuating device, cut-off valves and the fuel supply device, ilows through the pipe 5 into the switch cabinet Inthe pipe 5 there is provided the three-way cock 41 which can be moved by means of a handle 3 projecting outside the housing. The position of the handle 3 shown on the drawings'and of the cock 41 is the normal position. In this position of the cock 41 the pressuremedium can flow into the pipe 5a and from there also into the pipe |92 which leads to the supply device.

If the hand lever 3 of the cock 41 is move upwards the connection of the pipe 5a -with the pressure medium pipe 5 is interrupted and the pipek 5a is connected with a pipe 2|1 for pressure medium released from pressure. The pipe 2|1 leads to the collecting pipe 6 for pressure medium released from pressure.

The door 2 leading into the inside of the switch cabinet isA closed by means of the bolt 4 which is likewise operated by the lever 3. As can be immediately seen from the drawings the door 2 of the switch cabinet can only be opened if the cock 41 is moved to pressure release position and therefore the pressure medium supply from the pipe 5 interrupted. It is thus not posy control apparatus has been stopped by cutting.

off the supply thereto of the pressure medium. The bolt 4 is, moreover; preferably so constructed that it cannot be moved downwards so long as the door 2 of the switch cabinet is open. These special means for the bolt 4 are omitted from the drawings for the sake of simplicity.

On the inside of the' door 2 there are also provided one or more hooks 2|8 behind which engage the ends 2|9 of angle check levers 220, which pivot on the fixed pin 22|. The angle lever v220 engages in a recess of the check bolt 60 in such `a way that the lever 220, on moving the check bolt towards the right (on the drawings) is moved in a clockwise direction. Through this movement the end 2|8 of the angle lever 220 is brought under` the hook 2|8 and thereby the door 2 is bolted. v

In a similar way checking levers 220 are also provided for the other check bolts, for example, for the check bolt |23, the check lever 222.

The door 2 can thus only be opened if the vcheck bolt is in the position shown on the drawings. This is, however. the position in which the cut-off operating valves are all closed. The

switch cabinet `can thus only be opened if the.

nipulation of the levers (220, 222, etc.) as required by the position of the cams on the cam discs (26, H5, etc.).

For controlling the valves which control the `messure medium current to the valves or groups of valves cam discs are provided in the devices illustrated, but instead of these it is, however, also possible to use other similar members, for example endless chains, which are'provided with adjustable co-operating members and are stretched between two or more chain wheels which are connected with the driving motor.`

On the drawings the device is only illustrated schematically `in accordance with requirements. It is quite obvious to a technician that the principal members shown can be substituted by the `usual practical devices for water-gas plants.

' Various changes may be made in the details l disclosed in the foregoing specification without departing from the invention in all its aspects and the advantages thereof.

In the claims affixed to this specification no selection of any `particular modification of my invention is intended to the exclusion of other modifications thereof.

I claim:

1. In apparatus for automatic sequential control of flu-id pressure operated valves, a main drive shaft; a control disc thereon;` a pilot valve for controlling the operation of an operating valve; actuating means operable by the control disc for actuating the pilot valve, two

` oppositely disposed arresting cams on the control disc, a check bolt reciprocable into and out of engagement with the arresting cams whereby further movement of the control shaft is checked by one arresting cam during opening movement by the pilot valve and by the other arresting cam during closing movement by the pilot valve, a fluid pressure operated cylinder for reciprocating the check bolt; fluid pressure lines therefor each having a valve controlled by the open and closed positions of the operating valve; and timing device operable by iiuid pressure in one of the lines controlled by a valve operated by the operating valve in its end' position, for timing the open position period of the operating valve, and cut-oli valve means operable by said timing means for controlling the flow of fluid pressure in one of the lines to the check bolt operating cylinder, to release the main drive shaft for further movement. V

2. Automatic control according to claim 1, characterised in that with the timing device "there is connected an adjustable stop through the adjustment of which the time in which the' cut-off valve means is opened by the timing de- Yvice can be varied.

3. Automatic control according to claim 1, characterised in that from the operating valve in the end position twov valves are operated, one of which controls the flow in a pressure medium supply pipe and the other a connection of the pressure medium supply pipe to an exhaust pipe fior pressure medium released from pressure, and .in which the two valves are disposed so that with the opening of one valve the other is closed.

4. .Automatic control according to claim 1, characterised in that the cut-off valve means `which is operated by the timingdevice and which controls the ilow of pressure medium in one of the lines to the hydraulic cylinder for the check holt, is provided with and can be opened by a hand lever. l

5. Automatic control according to claim 1, 75

characterised in that a common electric motor is -provided for the control Adiscs for a series of operating valves or valve groups.

6. Automatic control according to claim 1, characterised in that all of the control members for the valves or valve groups except the valves operated by the operating valve are arranged in a closable housing which is provided with a door whose closure member is interlocked with a main cut-off cock for the supply of pressure medium in such a way that thecock is closed if the door is open.

'7. Automatic control as claimed in claim 1 in which the cut-off valve-means which is operated -by the timing device, and which controls the flow of pressure medium in one of the lines to the pressure cylinder for the check bolt is provided with and is capable of operation by a hand lever to open the same for ow to release the check bolt, and in which the hand lever is connected to be operated by the operation of a cutoi lever and valve therefor which, when operated, closes a pressure medium branch supply line which leads to similar mechanisms for operating another operating valve or valve group which is to be operated next in the cycle of operations.

8. Automatic control as claimed in claim 1. and in which a discharge closure for a charging vcontainer acting as a seal on aA gas producer cover, a closure controlling the filling opening to this container, and an outlet opening closure of a fuel supply hopper for the filling opening, are each provided with a fluid pressure operated operating device, and in which the pressure medium lines to these operating devices are provided with means connecting them to receive pressure medium from the cut-01T valve-means that is operated by the timing device before operation thereby, and in which the pressure medium lines to` these operating devices are controlled by hand cut-ofi cocks which are connected with each other in a manner to be operated only in a predetermined sequence, and in which the pressure lines for the fuel supplying devices are connected to intercept the pressure medium line which leads from the cut-oli valve means, that is operated by the timing device, to the pressure cylinder for the check bolt.

9. Automatic control as claimed in claim 1, and in which a discharge closure for a charging container acting as a seal on a gas producer cover, a closure controlling the lling opening to this container, and an outlet opening closure of a fuel supply hopper for the lling opening, are each provided with a fluid pressure operated operating device, and in which the pressure medium Zines to these operating devices are provided with means connecting them to receive pressure medium from the cut-off valve-means that is operated by the timing device before operation thereby, and in which the pressure medium lines to these operating `devices are controlled by hand cut-oli cocks which are connected with each other in a manner to be operated only in a predetermined sequence.

10. Automatic control as claimed in claim 1,' and in which a'discharge closure for a charging container acting as a seal on a gas producer cover, a closure controlling the filling opening to this container, and an outlet opening closure of a fuel supply hopper` for the filling opening, are each provided with a fluid pressure operated operating device, and in which the pressure medium lines to these operating devices are controlled by hand cut-off cocks which are connected with l, o y

each other in a manner to be operated only in a predetermined sequence, and in which the pressure medium lines to the pressure operated supply devices and the pressure medium line which.l

leads from the cut-o` valve-means that is actuated by the timing device to the pressure cylinder for the check bolt are connected in such manner by a reversing cock that on opening the l pressure line to the pressure operated supply de- `movement of the timing device in one direction by restraining its movement under the iluid pressure, while still allowing it to move, under its fluid pressure, against the brake-action of the brake-element therefor.

12. Automatic control as claimed in claim 1, and in which the operating-valve-controlled uid pressure line that operates the timing device leads to and ls `controlled by the cut-off valve means, and in which the timing device, after reaching its end position, actuating the cut-off valvemeans, is freed from the pressure medium in said line by the release of said line by the ac-Y tuation of the cut-off valve means, and in which while still allowing it to move, in order to determine the speed of movement of the timing device for the cut-oil? valve means.

14. In apparatus for automatic sequential control of uid pressure operated valves, a series of pilot valves so constructed as to control the flow of fluid pressure to the respective operating valves; sequence. control elements mounted for fluid pressure operated means are provided for automatically returning the timing device to its initial position.

13. Automatic control as claimed in claim 1, and in which an electric motor, adapted to run with a constant speed of rotation, is connected with the timing device through gearing adapted to restrain the movement of the timing device rotation in unison so arranged as to determine the sequence of movements of the respective pilot valves; actuating means so constructed as to be operableby the sequence control'elements for operating the respective pilot valves; stop means for the respective sequence control elements so arranged as i to arrest all the control elements when one actuates its pilot valve; fluid pressure operated release means for Vthe respective stop means having pressure lines leading thereto irom the operating valves, for operation of the release means by iiuld pressure from the operating valves on the end position of the operating valve; valve means interposed in the latter lines and so constructed as to interrupt the flow of fluid pressure from the operating valves to the release means; and timing means operable by Iluid pressure in said latter lines and so arranged as to actuate the interposed valve means and constructed to be set to effect the actuation after a'set'interval of time to release the ow of fluid pressure from the operating valves to the release means to actuate the same,A and thus determine the duration of the period of time the operating valves remain open before their pilot valves are actuated by further movement of the sequential control elements to close the operating valves. JOSEPH DANIELS. 

